Abstract
We have used Auger electron spectroscopy as a direct measure of silicon segregation in molecular beam epitaxy grown delta-doped GaAs. We find that this technique allows very precise detection of Si segregation. Spectra have been obtained, as a function of temperature, from samples in which Si has been deposited in the normal delta doping manner and then typically 10 Å of GaAs deposited on top. Si segregation is manifested at higher temperatures by the absence of the expected attenuation of the Auger signal. Our results show that Si segregation in GaAs is measurable at temperatures above 520 °C.